Dental prophylaxis right angle hand piece



Jan. 5, 1965 A. D. WISEMAN 3,163,934

DENTAL PROPI-IYLAXIS RIGHT ANGLE HAND PIECE Filed Sept. 14, 1962 FIG 3 FIG 4 INVENTOR ADOL PH 0. WISE MAN BY e fihmwuni v A T TORNEVS United States Patent This invention relates to dental right angle hand pieces, and has for one of its objects the provision of such a hand piece that is permanently assembled, long lasting, economical to make, safer in use than heretofore, and far less fatiguing on the dentist than conventional hand pieces.

Another object of the invention is the provision of a dental, right angle hand piece that i more comfortable for the patient when the hand piece is being used for prophylaxis, than heretofore.

An additional object is the provision of a hand piece that is more sanitary than the ordinary hand pieces heretofore used, in that infected material cannot become lodged within the hand piece, thus requiring no disassembly of the hand piece, and all parts exposed to contamination are readily sterilized by cold solution, boiling liquid, steam or autoclaving without detriment to the hand piece.

A still further object of the invention is the provision of a dental, right angle hand piece that is more economical to make than the conventional hand pieces heretofore used, am also one that is more durable and in which the bearings are not subjected to contact with the abrasives that are used for cleaning and polishing teeth.

In explanation of some of the foregoing objects and advantages, dental right angle hand pieces have heretofore been made of metal, and have therefore been cold and uncomfortable for the patient, and painful and damaging to the teeth upon striking the latter, as frequently occurs during the cleaning and polishing of the teeth.

The exposed portion of the present hand piece is of plastic material, preferably such as polypropylene, which is relatively soft as compared with metal and has excellent shock absorbing properties. Also, it is relatively warm to the touch when compared to metal, and is only a small fraction of the weight of metal.

Conventional hand pieces of the present type must be disassembled for sterilization and cleaning, since the moisture from within the mouth of the patient, including pumice or whatever abrasive may be used, will enter the hand piece. In disassembling the ordinary hand pieces heretofore in use, wrenches are required and there is a substantial loss in time, to say nothing of the possible loss of or misplacement of parts of the hand piece, in the disassembling and assembling of the hand piece. With the present hand piece it is merely necessary to uncouple it from the conventional Doriot type handle through which a drive shaft extends, and to efiect the sterilizatior thereof in the usual manner without disassembling it.

Other objects and advantages will appear in the description and drawings.

In the drawings FIG. 1 is a vertical cross sectional view taken through the hand piece, the metal parts being shown in elevation and also a portion of the plastic housing being shown in elevation.

FIG. 2 is an end view of the hand piece of FIG. 1 as seen from the outer end with a flexible abrasive applying element or cup attached thereto.

FIG. 3 is an enlarged, cross sectional view of one of the parts of the hand piece.

FIG. 4 is a part sectional, part elevational View of a portion of the hand piece assembled. I

FIG. 5 is an enlarged fragmentary sectional view of a 3,153,934 Patented Jan. 5, i965 portion of the housing that is complementary to one of the parts of FIG. 4.

In detail, the hand piece housing is generally designated 1, and comprises an elongated tubular portion 2 that opens outwardly at one end thereof, and the part of this portion that is adjacent to said open end is exteriorly formed with a roughened finger graspable surface that may be in the form of ridges 3 extending longitudinally of said part. The marginal portion at said open end is cylindrical and is-formed with a pair of parallel slots 4 extending longitudinally of said portion 2 at two opposite sides thereof, and that open outwardly at said open end. This is conventional structure in the Doriot type hand pieces to provide for connecting thet hand piece with the conventional coupling or fitting that in turn is connected with the source of power.

The external surface of the part 3 is slightly convergent in a direction away from the open end of the tubular portion 2, at a point 5 intermediate the opposite ends of portion 2, and at the convergent end of part 3, the external diameter of the portion 2, relatively abruptly decreases and then the exterior diameter is of substantially cylindrical uniform diameter, as at 6, terminating in a right angle elbow '7 and a short cylindrical portion 8- projecting at a right angle to the axis of the portion 2. The outer end of the right angle portion 8 is open. This right angle elbow may be called the nose portion or nose of the housing, and it is exteriorly rounded so there are no sharp projections.

The portion 2 is formed with a cylindrical sided bore that is of enlarged diameter at the open end thereof and that tapers to a reduced diameter bore 10, the latter being further slightly reduced in diameter adjacent to the nose 7 to provide a slight annular shoulder 11 that faces toward the open end of the portion 2, and a reduced diameter cylindrical continuation 12 of bore 10. The nose portion 7 i interiorly formed with a recess 13 that is coaxial with the cylindrical right angle projection 8, and that opens toward the open side of the nose.

The inner side of the projection 8 is formed with a radially inwardly opening annular recess 15 (FIG. 5), the bottom of which is preferably rounded, as at 16, and the outer side 17 nearest the open side of the nose 7 extends radially inwardly rather abruptly, while the opposite side 18 extends slantingly toward the axis of cylindrical portion 8 in a direction away from the open side of nose 7, and terminates and then continues toward recess 13 in a cylindrical portion 19 that is of a substantially greater diameter than, that of recess 13, and of approximately the samediameter as the inside diameter of portion 8.

A socket gear 22 is adapted to be positioned within the portion 12 of bore 10 that is adjacent to the nose 7, while a similar socket gear 23 is adapted to be positioned within the cylindrical portion 19 within the nose 7. These gears have axially projecting teeth that mesh with each other, the axes of the gears being positioned at a right angle to each other, with the axis of gear 22 coaxial with bore 2 and with the axis of gear 23 being coaxial with recess 13 and the cylindrical inner surface 19 and the projection 8.

An elongated spindle 24coaxial with gear 22 is pinned at one of its ends to said gear and is adapted to extend through the bore 10 coaxial therewith, while a shorter spindle 25 (FIG. 4) is adapted to be pinned to gear 23.

FIG. 4 illustrates the nose spindle assembly that includes the nose gear 23 and nose spindle 25. This nose spindle, as viewed in FIGS. 1 and 4, has a reduced diameter upper end portion 26 that is adapted to rotatably extend into recess 13, and a ball 27 (FIG. 1) positioned between the upper end of the shaft and the closed upper end of the recess 13 whcn the nose spindle assembly is in its operating position. Thus the ball 27 functions as a thrust bearing for the'spindle.

tending to the flange -31.

- 3 The lower end of the nose spindle projects out of the nose through the portion 8 thereof and it may be formed at its lower end with a bulbous portion 28 that is adapted to fit within a socket in a flexible dental tool '28 with an annular, radially outwardly projecting flange '31, the outside diameterof which is preferably substantially equal to the outside diameter of the projection 8 of nose 7. When the base .32 of the member 29 is secured over the bulbous end 28, the outside diameter of the base 32 will project slightly radially outwardly of the flange 331, but this base will be tight against the axially outwardly facing surface of the flange 31.

The spindle .25 and the flange 31 and end portion '28 are all of suitable metal as is the ball 27.

A nylon bearing 33 is adapted to rotatably support the cylindrical shank 34 of gear '23 (FIG. 4), the latter ex- Bearing 33 is exteriorly formed with a radially outwardly projecting annular flange 35 that is of the same outside diameter as that of the flange 31, while the radially outwardly facing surfaceof the bearing that adjoins the flange 35 is complementary in cross sectional contour to the radially inwardly facing surface of the projection 8 between the cylindrical surface 19 and the outer end of said projection 8.

When the nose assembly of FIG. 4 is made, and after ball 27 is positioned within the recess 1-3, the assembly is moved axially of spindle 25 into the nose 7 through its open side and the radially outwardly projecting annular ridge 38 on the bearing 33 will snap into the radially inwardly opening recess '15 in the nose 7, thereby holding the nose spindle assembly within the nose, with the spind-le 25 rotatable within bearing '33. Once the nose spindle assembly is held within the nose 7, as above described, it cannot be removed.

A'suitable conventional silicone lubricant is first placed within the nose, and surrounds the spindle. No moisture or foreign material can work its way into the nose past the flange 31 or between the flange 31 and the flange 35, and the fit'between the bearing 33 and the outside housing is tight.

To distinguish the spindle assembly that includes the gear 22 and spindle 24 from the nose spindle assembly, it will be called the handle spindle assembly, since the portion 2 of the housing generally functions as a handle, being grasped by the uingers of the dentists hand.

This handle spindle assembly includes'a nylon bearing 39 that is adapted to have a press fit in'the bore 10 and this bearing has an enlarged end that abuts the shoulder 11, and a reduced diameter end portion 40 that projects toward the open end of the portion 2.

A metal locking collar 41 (FIG. 3) fits around the reduced diameter portion 40 of bearing 39, and this collar is exteriorly formed with a coaxial row of annular teeth 42, the sharp edges of which are generally directed toward the open end of portion 2. The outside diameter of the collar 41 is such that the teeth 42 will be impressed into the inner surface of the bore of the housing when the collar is forced into bore 10Ito prevent'retraction of the collar and bearing 39 from the'handle 2. V

The nose, as already explained, has been packed with the water repellant lubricant, so that the gears and spindles will be adequately lubricated, but no moisture can leak past the bearing. The spindle 24 and gear 22 and :the locking collar 41 are preferably of metal.

without disassembly, other than removing the abrasive applying portion 29. The tedious and time consuming operation of disassembling the tool with a wrench and reassembling it are not necessary.

The hand piece weighs less than 15 grains, whereas the conventional metal handpiecemay weigh up to approximately grains. Thus the fatiguing that follows the use of the conventional hand piece is largely overcome.

If the nose of the hand piece should strike 'a tooth, there is no material shock .to the tooth, nor is there any damage to the tooth. Also the contact between the nose or housing and the tissue Within the mouth does not result in a cold shock, since the plastic material is relatively warm.

It is to be understood that the detailed description is not intended to place any limitations on the invention, since they are by way of example, and the invention is intended to extend to all modifications that may come within the scope of the appended claims.

I claim:

1. A dental prophylaxis right angle hand piece comprising:

(a) an elongated tubular member having a bore therein extending axially thereof openingoutwardly of said member at one end thereof and a hollow, right angle nose portion formed integrally with said tubular member at the'end thereof opposite to said one end providing a gear chamber with said bore opening into the latter;

(b) an opening formed in one side of said nose portion opening into said gear chamber at a right angle to the axis of said bore;

(0) a drive spindle rotatably supported in said bore having a drive gear at said nose portion;

(a') a nose assembly including 'a driven spindle having a driven gear secured on one end portion thereof; means for holding a dental implement on the other end, and a seal-bearing coaxial with said spindle between said drive gear and said means;

(2) said opening being of sufiicient diameter to pass said driven gear therethrough into said gear chamber;

(f) the sides of said opening and said seal-bearing having complementarily formed interengaging means movable into holding and sealing relation upon said nose assembly being bodily moved axially of said spindle to pass said driven gear through said opening into said chamber to driving relation'with said drive gear, and said interengaging means being in said interengaging relation with said driven gear in said driving relation with said drive gear for being driven thereby and with said means for holding said dental implement projecting from said nose portion.

2. In a construction as defined in claim 1,

(g) said interengaging means being an annular, radially inwardly opening recess around the sides of said opening and an annular'radially outwardly project ing ridge around said seal-bearing;

(h) the material of said nose portion being resilient to enable said ridge to snap into said recess upon said axial movement of said'nose assembly and seal-bearing.

3. In a construction as defined in claim 2, said annular radially outwardly projecting ridge being adjacent to said driven gear and having a slanted surface nearest to said gear extending from said gear outwardly and in a direction away from the latter to facilitate the movement of said ridge into said opening to said recess.

4. A dnetal prophylaxis right angle hand piece comprising;

(a) a onepiece elongated tubular member having a bore therein extending axially thereof opening outwardly of said member at one end thereof and a hollow, right angle nose portion formed integrally with said tubular member at the end thereof opposite to said one end providing a gear chamber with said bore opening into the latter at the end of the latter opposite to said one end of said member;

(b) an opening formed in one side of said nose portion opening into said gear chamber at a right angle to the axis of said bore;

(c) a drive assembly including an elongated drive spindle having a drive gear secured on one end thereof and a sleeve-bearing adjacent thereto in which said spindle is rotatable;

(d) the minimum diameter of said how being greater than the diameter of said drive gear and at least equal to the outside diameter of said sleeve bearing which is press fit in said bore adjacent to but spaced from said gear chamber whereby said drive assembly may be inserted as a unit into said bore with said sleeve holding said drive gear at said gear chamber;

(e) said drive gear assembly being in said bore with said sleeve tightly held by the walls thereof at said gear chamber supporting said gear in a position with its teeth projecting into the latter;

(1) an opening formed in one side of said nose portion opening into said chamber at a right angle to the axis of said bore; a

(g) a nose assembly including a driven spindle having a driven gear secured on one end thereof, means for holding a dental implement on the other end and a seal-bearing coaxial with said spindle between said drive gear and said means;

(h) said opening being of sufiicient diameter to pass said driven gear therethrough and into said gear chamber, and means on said nose portion at said opening and on said seal-bearing movable into sealing and holding relation upon movement of said gear through said opening and into said chamber'to mesh ing relation with said drive gear, whereby said nose assembly may be moved into holding operating relation with said nose portion as a unit, and said driven gear being within said gear chamber in meshing relation to said drive gear with said means on said nose portion and on said seal bearing in sealing and holding relation.

References Cited in the file of this patent UNITED STATES PATENTS 1,982,336 Wiseman Nov. 27, 1934 2,051,718 Kaltenbach et a1. Aug. 18, 1936 2,135,933. Blair Nov. 8, 1938 2,861,462 Hussar Nov. 25, 1958 

1. A DENTAL PROPHYLAXIS RIGHT ANGLE HAND PIECE COMPRISING: (A) AN ALONGATED TUBULAR MEMBER HAVING A BORE THEREIN EXTENSING AXIALLY THEREOF OPENING OUTWARDLY OF SAID MEMBER AT ONE END THEREOF AND A HOLLOW, RIGHT ANGLE NOSE PORTION FORMED INTEGRALLY WITH SAID TUBULAR MEMBER AT THE ONE THEREOF AOPPOSITE TO SAID ONE END PROVIDING A GEAR CHAMBER WITH SAID BORE OPENING INTO THE LATTER; (B) AN OPENING FORMED ON ONE SIDE OF SAID NOSE PORTION OPENING INTO SAID GEAR CHAMBER AT A RIGHT ANGLE TO THE AXIS OF SAID BORE; (C) A DRIVE SPINDLE ROTATABLY SUPPORTED IN SAID BORE HAVING A DRIVE GEAR AT SAID NOSE PORTION; (D) A NOSE ASSEMBLY INCLUDING A DRIVEN SPINDLE HAVING A DRIVEN GEAR SECURED ON ONE END PORTION THEREOF; MEANS FOR HOLDING A DENTAL IMPLEMENT ON THE OTHER END, AND A SEAL-BEARING COAXIAL WITH SAID SPINDLE BETWEEN SAID DRIVE GEAR AND SAID MEANS; (E) SAID OPENING BEING OF SUFFICIENT DIAMETER TO PASS SAID DRIVEN GEAR THERETHROUGH INTO SAID GEAR CHAMBER; (F) THE SIDES OF SAID OPENING AND SAID SEAL-BEARING HAVING COMPLEMENTARILY FORMED INTERENGAGING MEANS MOVABLE INTO HOLDING AND SEALING RELATION UPON SAID NOSE ASSEMBLY BEING BODILY MOVED AXIALLY OF SAID SPINDLE TO PASS SAID DRIVEN GEAR THROUGH SAID OPENING INTO SAID CHAMBER TO DRIVING RELATION WITH SAID DRIVE GEAR, AND SAID INTERENGAGING MEANS BEING IN SAID INTERENGAGING RELATION WITH SAID DRIVEN GEAR IN SAID DRIVING RELATION WITH SAID DRIVE GEAR FOR BEING DRIVEN THEREBY AND WITH SAID MEANS FOR HOLDING SAID DENTAL IMPLEMENT PROJECTING FROM SAID NOSE PORTION. 